The present invention relates to a hand scanner which is used for computers, facsimiles and others for reading images.
Since the hand scanner is manually moved for reading an image, it is advantageous to read images on filed papers or in a book.
FIG. 6 is a plan view showing a conventional hand scanner, and FIG. 7 is a sectional side view of the scanner.
Referring to FIGS. 6 and 7, a hand scanner 50 has a case 51 in which a roller 52 is rotatably mounted and a linear image sensor 55 is provided. The axis of the roller is disposed in the Y-direction, and the periphery of the roller projected from an opening 51a and mounted on a printed sheet 60. The linear image sensor 55 comprises a plurality of optical sensors such as the CCDs which are aligned in the Y-direction within the width W.
The shaft of the roller 52 is connected to an encoder disk 53 through gears. The rotation of the encoder disk 53 is converted to an electric signal by a photointerrupter 54.
The scanner having the width W larger than the width of the printed sheet is used. The roller 52 is manually moved on the printed sheet 60 in the X-direction. The rotation of the roller 52 is converted into an electric signal by the photointerrupter 54 as a travel distance of the scanner. During the movement of the scanner, outputs of the CCDs are sequentially transferred by a shift register (not shown) to read an image on the sheet 60.
There is no problem in the case where the width W is larger than the width of the printed sheet 60. However, if the width of the sheet is larger than the width W of the scanner, it is difficult to read the image on the sheet.
Referring to FIG. 8, the width of a printed sheet 61 is larger than the width W of the scanner 50. In order to read an image 56, the scanner must separately scan an upper portion 61a and a lower portion 61b. First the upper portion 61a is read out, and then the lower portion 61b is read out.
The image data of the upper portion 61a and the lower portion 61b are once stored in a computer or a facsimile machine. However, since the width w of an overlap portion 61c is unknown, the overlap portion can not be erased. Therefore, when the read out images are printed, upper image 56a and lower image 56b are printed as it is as shown in FIG. 10. Consequently, the images 56a and 56b must be corrected by composition of both images.
The composition operation will be described hereinafter with reference to FIG. 9. After scanning the upper portion 61a and the lower portion 61b at steps S11 and S12, it is determined whether the composition is executed after the printing of the images at a step S13. If it is the case, the images are printed at a step S14. The overlap portion is cut off, and both sheets are manually joined at a step S15 to form the original image. It should be noted that when image data are stored in the facsimile machine, the program inevitably proceeds to the step S14 from the step S13.
When the image data are composed before printing, the program proceeds to a step S16, where the image data may be composed by software in a computer system and by a manual difficult operation.
As described above, in the conventional scanner, when scanning a paper sheet having a larger width than the scanner, it is necessary to execute difficult manual operation to compose separate images to an original image.
An object of the present invention is to provide a hand scanner which may compose image data to an original image without manual operation.
According to the present invention, there is provided a hand scanner having an image reading portion in which a linear image sensor is provided for reading an image on a paper sheet, comprising, an X-roller disposed in an X-direction, a Y-roller disposed in a Y-direction perpendicular to the X-direction, both the X-roller and Y-roller being disposed in a horizontal plane, a spherical ball contacted with the X-roller and the Y-roller and provided to be contacted with the paper sheet, first detector means for detecting an angular position of the X-roller to produce an X-position signal for determining an X-coordinate, second detector means for detecting an angular position of the Y-roller to produce a Y-position signal for determining a Y-coordinate on the paper sheet.
In an aspect of the invention, the scanner further comprises urging means for urging the spherical ball to the X-roller and Y-roller so that both the rollers are rotated together with the spherical ball.
Each of the first and second detector means comprises an encoder disk provided on a shaft of either of the X- and Y-rollers and a photointerrupter for detecting an angular position of a corresponding encoder disk.
The X-roller, Y-roller and the spherical ball may be disposed adjacent the image reading portion.
The urging means comprises a roller and a spring for urging the roller to the spherical ball.
These and other objects and features of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings.